Alloys are useful in various applications owing to their special characteristics. Alloy structural parts are generally prepared by die-casting or thixo molding. For alloys structural parts containing at least two metals materials, since different metals may have different shrinkages, defects (such as sink marks, shadows, pinholes, blowholes etc.) inevitably appear on the surfaces of the alloys structural parts after die-casting or thixo molding. Some suppliers rework the defective alloy structural parts surfaces by repeatedly applying coatings thereon and polishing the coated alloys structural parts for several cycles, for example, for four or five cycles,
Reference will now be made to some illustrative examples, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended.